Magnetic retractable door roller for automatic elevators



Aug. 15, 1961 G. OLEXSON ET AL 2,996,152

MAGNETIC RETRACTABLE DOOR ROLLER FOR AUTOMATIC ELEVATORS F'iled April 6, 1960 4 Sheets-Sheet 1 JNVENTORS GEORGE OLEXSON BY PETER FINN Aug. 15, 1 61 G. OLEXSON ETAL MAGNETiC RETRACTABLE DOOR ROLLER FOR AUTOMATIC ELEVATORS A 4 Sheets-Sheet 2 F'iled April 6, 1960 INVENTORS GEORGE OLEXSON BY PETER FINN Aug. 15, 1961 G. OLEXSON ETAL MAGNETIC RETRACTABLE DOOR ROLLER FOR AUTOMATIC ELEVATORS 4 SheetsSheet 5 Filed April 6. 1960 INVENTORS GEORGE OLEXSON BY PETER FINN Aug. 15, 1961 G. OLEXSON ETAL MAGNETIC RETRACTABLE DOOR ROLLER FOR AUTOMATIC ELEVATORS F'iled April 6, 1960 4 Sheets-Sheet 4 TO ELEVATOR MOTOR CIRCUIT INVENTORS GEORGE OLEXSON y PETER FINN ATTOP/V') United States Patent 2,996,152 MAGNETIC RETRACTABLE DOOR ROLLER FOR AUTOMATIC ELEVATORS George Olexson, 660 Humbolt St., New York, N.Y., and Peter Finn, 8223 Bay Parkway, Brooklyn, N.Y. Filed Apr. 6, 1960, Ser. No. 20,432 Claims. (Cl. 187-52) This invention concerns a device for opening elevator entrance doors at the several floors of a building.

Heretofore sliding elevator entrance doors have been opened by the engagement of door opening members carried by the sliding door of the elevator cab or cage with rollers carried by the elevator entrance doors. The door opening members on the door of the elevator cab have included two spaced, parallel bars disposed vertically. A roller extending outwardly from the elevator entrance door at each floor of the building would pass between the bars. When the elevator stopped and its door opened, the entrance door of thebuilding opened with the door of the elevator cab. The rollers protruding from each door at each floor were made of rubber to cushion the shock of impact when the rollers struck the parallel bars. The rollers were supported on' levers which carried contacts of an interlock switch in the elevator drive motor circuit. When the elevator cab door opened the interlock switch opened and the drive motor was held stopped. Frequently due to wear and misalignment the rollers were struck as the elevator cab passed floors where the elevator was not called to stop, causing the interlock switch to open and the elevator cab was stopped. Also the elevator entrance door might bereleased to open. This rendered the elevator inoperative until the defective door roller was repaired.

The present invention is directed at eliminating this source of trouble by providing a novel door opening structure in which the door opening rollers are held out of the path of movement of the bars on the elevator cab door until the elevator cab is actually at the floor where it' is to stop. The roller at that floor is normally in 'a retracted condition and is pulled outwardly between'the parallel bars as the elevator stops. As the elevator cab door opens the elevator entrance door at that floor opens also due to engagement of the roller between the parallel bar s.

Associated with the parallel bars is an electromagnet which is energized when the elevator cab arrives at the Floor where it is to stop. The roller is formed from magnetic material and is attracted by the electromagnet against a spring bias tending to hold the roller retracted. After the two doors open and close, the electromagnet s deenergized, the roller retracts, and the elevator is free move on to another floor.

It is therefore a principal object of the invention to srovide a sliding door opening mechanism for an eleva- :o r including a retractable roller adapted to be extended For engagement with door opening bars on an elevator :ab.

A further object is to provide a sliding door opening mechanism including a roller normally retracted on a :upport by a spring and adapted to be extended against ension in the spring by attraction of an electromagnet ncluding parallel bars spaced toreceive the roller in exended condition therebetween.

A still further object is to provide a sliding door openng mechanism of the character described, wherein the suport for the roller includes a lever adapted to operate LII interlock switch of an elevator motor drive circuit.

For further comprehension of the invention, and of the )b'jects and advantages thereof, reference will be had 0 the following description and accompanying drawings, tnd to the appended claims in which the various novel ice features of the invention are more particularly set forth.

In the accompanying drawings forming a material part of this disclosure:

FIG. 1 is a front elevational view of an elevator cab showing in section a portion of a door opening roller according to the invention.

FIG. 2 is a vertical sectional view taken on line 22 of FIG. 1, showing details of the elevator cab door, elevator entrance door, and door opening mechanism.

FIG. 3 is a front elevational view on an enlarged scale of the electromagnet as associated with parallel bars.

FIG. 4 is a rear view of the structure of FIG. 3.

FIG. 5 is a perspective view of the structure of FIG. 3.

FIG. 6 is a perspective view of components of the electromagnet in partially assembled form.

FIG. 7 is an elevational rear view of the roller and support on an enlarged scale.

FIG. 8 is a top plan view of the roller and support.

FIG. 9 is a central sectional view on an enlarged scale of the parts shown in FIG. 8. I

FIG. 10 is a diagram of part of the interlock switch circuit and associated parts of the roller support.

FIG. 11 is a diagram showing in simplified form, one way in which the electromagnet may be energized and .deener'gized when installed in an elevator according to the invention. i

Referring to FIGS. 1 and 2, there is shown an elevator cab'20having a sliding cab door or gate 22. The door is guided for movement in its'plane by tracks 24', 26 on a track plate 28. Sheaves 25 and 27 supported on brackets 29, 30 roll on the respective tracks. The door lugs 32 project from its lower end into a g'roove'34 in the floor 35 of the elevator cab; see FIG. 2.

Mounted vertically on the front of the door 22 'by brackets 33 is a rail 36 having a groove 38 in which slides a roller 40 on the end of a lever arm 42. Arm 42 is rotated by a wheel 43 driven by chain 44. The chain is driven by sprocket gear 46 keyed on shaft 47 with pulley wheel 48. The pulley wheel is' driven by belt.'49"'entrained on pulley 50 of motor 52. The motor is energized to open the elevator door by causing arm 42mmtate as indicated by the arrows in FIG. 1. A' gate or door switch 54 having an'arm 56 is engaged by upper sheave 27 when the door 22 is closed. A stop member 58 carried by bracket 59 on the roof 57 of the cab serves to limit upward movement of the arm 42.

Mounted adjacent to the brackets '33 and rail 36 'is electromagnet assembly 60'forming one partof the door opening mechanism. This assembly, as shown to best advantage in FIGS. 3-6,includes a rectangular metal plate 62 provided with holes 63 for receiving screws or bolts 61 by which it is secured to the door 22. Secured to the plate 62 by screws 65 is a smaller rectangular magnetic plate 64 formed of steel. Attached to plate 64' by screws 66 are two spaced magnetic steel blocks 68, 69 which serve as pole pieces. Secured to the inner sides of the blocks by screws 70 are two spaced parallel magnetic bars 71, 73 extending vertically above andbelow the plate 62. A pair of insulation wrapped coils 72', 74 are wound around the blocks 68,69. The coils have terminal wires 76, 78 which may be connected in an energizing circuit to be described.

An elevator entrance door 80'at one floor of a building is shown in FIG. 2. This sliding door is supported by sheaves 82, 84 riding on rails 86 secured to wall 90 of the building. Projecting from the bottom of the door 80 are lugs'92 which ride in a groove 93; 'in the floor 94 of the building. Mounted on the rear of the door is a' roller assembly shown to best advantage in FIGS. 7-9, to which reference is now made. The roller assembly includes a rectangular mounting plate 102 in which is fixed by screw 103 a pin 104. On this pin, held by washer 101 and cotter pin 107, pivots a lever 106. The lever has a laterally extending curved finger 108 which engages a stop member 110 when the lever is tilted. Secured to the lever in a hole 110 is a post 112 having a flange 113 at its outer end abutting the lever. The post is secured to the plate by a nut 114 and a setscrew 116. Secured to the flange 112 by screws 118 is a cup-shaped member 120 having a hole 122 at its outer end 132.

A cup-shaped roller 124 is axially slidable on the outside of member 120. Secured to the inner circular side of the roller is a threaded pin 126 having a flanged head 128. A coil spring 130 is mounted on the pin between the head 128 and the circular end 132 of the member 120. Roller 124 has an annular flange 134. The roller is formed of magnetic metal and is adapted to be attracted by the electromagnet assembly to be extended between the bars 71, 73 as indicated by dotted lines in FIG. 9. Pivotally attached to a slotted finger 135 formed integral with lever 106 is a link 140. This link is connected by an extension 141 to a switch arm 142 of an interlock door switch (see FIG. pivotally mounted in a switch box 144 on the wall 90 above door 80. A thin rubber sleeve 123 can be secured to roller 124 if desired.

FIG. 10 shows in simplified schematic form part of the interlock door switch 145 in switch box 144. This switch includes fixed contacts 146 on insulation plate 148 and movable contacts 147 carried on a conductive plate 150 on the end of arm 142. When the arm 142 is tilted counterclockwise as viewed in FIG. 10, such as occurs when the door 22 starts to open and roller 124 is engaged and pulled by bar 71, contacts 146 are bridged. This causes relay 152 to be energized via power supply 164. Contacts 166 of relay 152 close and solenoid 160 is energized via power supply 162 to tilt bell crank 165 on door 80 and disengage catch 167 on wall 90 so that the door 80 may open. Relay 170 is also energized and its normally closed contacts 172 open. These contacts are in the power supply circuit of the elevator motor (not shown) and serve as an interlock switch to prevent the elevator motor from starting while the elevator is stopped and the doors are open.

FIG. 11 shows in simplified schematic form part of the circuit which energizes the electromagnet assembly 60. The electromagnet coils 72, 74 are energized by power supply 180 in series with normally open contacts 182 of relay 184. Relay 184 is in series with a conventional slow-down switch 186 and power supply 188. The slow-down switch is a conventional type of switch as usually employed in automatic elevators. This switch is closed when an elevator cab begins to slow down at a floor to which it has been called.

When switch 186 closes, the relay 184 is energized which closes contacts 182 and causes the coils 72, 74 to be energized so that the electromagnet 60 attracts the roller 124 as bars 71, 73 arrive opposite the roller. After the door of the elevator has opened and closed, the switch 186 is opened and the electromagnet becomes deenergized so that roller 124 is retracted by spring 130. The roller 124 is thus taken out of the path of movement of bars 71, 73 as the elevator rises or descends.

While we have illustrated and described the preferred embodiment of our invention, it is to be understood that we do not limit ourselves to the precise construction herein disclosed and that various changes and modifications may be made within the scope of the invention as defined in the appended claims.

Having thus described our invention, what we claim as new, and desire to secure by United States Letters Patent is:

1. In a door opener for an automatic elevator, a base plate, a magnetic plate carried by said base plate, pole pieces secured to said magnetic plate, connected coils wound around the respective pole pieces, and elongated magnetic bars secured to the respective pole pieces and extending parallel to each other, said bars having free ends extending beyond opposite ends of said base plate, said bars being spaced to receive a magnetic roller when the coils are energized to magnetize the magnetic plate, pole pieces and bars.

2. In a door opener for an automatic elevator, a base plate, a magnetic plate carried by said base plate, pole pieces secured to said magnetic plate, connected coils wound around the respective pole pieces, and elongated magnetic bars secured to the respective pole pieces and extending parallel to each other, said bars having free ends extending beyond opposite ends of said base plate, said bars being spaced apart a predetermined distance, a magnetic roller having a diameter less than the spacing of said bars to fit therebetween when the coils are energized to magnetize the magnetic plate, pole pieces and bars, a support, a cylindrical member mounted on said support, said roller being axially mounted on said member and movable axially thereon, and spring means retaining and retracting said roller on said member, said roller being extended and held between said bars only when the coils are energized.

3. In a door opener for an automatic elevator, a base plate, a magnetic plate carried by said base plate, pole pieces secured to said magnetic plate, connected coils wound around the respective pole pieces, and elongated magnetic bars secured to the respective pole pieces and extending parallel to each other, said bars having free ends extending beyond opposite ends of said base plate, said bars being spaced apart a predetermined distance, a magnetic roller having a diameter less than the spacing of said bars to fit therebetween when the coils are energized to magnetize the magnetic plate, pole pieces and bars, a support, a cylindrical member mounted on said support, said roller being axially mounted on said member and movable axially thereon, and spring means retaining and retracting said roller on said member, said roller being extended and held between said bars only when the coils are energized, said support including another base plate, a lever pivotally mounted on said other base plate, said cylindrical member being secured to said lever, an interlock switch, and a link operatively connecting said lever and interlock switch for actuating said switch when said roller is contacted by one of said bars.

4. A door opener for an automatic elevator, comprising a roller carried by a support adapted to be mounted on a slidable elevator entrance at a floor of a building, an electromagnet including guide bars adapted to be carried by a slidable gate of an elevator cab, said guide bars being spaced to receive said roller therebetween, spring means on said support normally retracting the roller out of the vertical path of movement of said guide bars when the elevator cab is ascending and descending, said electro magnet being operative to attract and pull said roller against spring tension between the guide bars when the roller is opposite the bars and the elevator cab is stopping at said floor, whereby the elevator entrance door will be opened with the gate of the elevator cab, said electro magnet further including a magnetic plate, pole piece: secured to the magnetic plate, connected coils wounc around the respective pole pieces, said guide bars being magnetic members secured to said pole pieces and extending parallel to each other with free ends extending beyond opposite ends of said plate, said support including a base plate, a lever pivotally mounted on said basr plate, a cylindrical member secured to said lever, sait roller being axially mounted and movable on said cylin drical member, an interlock switch, and a link operatively connecting said lever and interlock switch for actuating said switch when said roller is contacted by one of sai bars as the elevator entrance door is opened with the gatr of the elevator cab.

5. A door opener for an automatic elevator, comprising a roller carried by a support adapted to be mounted on t slidable elevator entrance at a floor of a building, a!

electromagnet including guide bars adapted to be carried by a slidalble gate of an elevator cab, said guide bars being spaced to receive said roller therebetween, spring means on said support normally retracting the roller out of the vertical path of movement of said guide bars when the elevator cab is ascending and descending, said electromagnet being operative to attract and pull said roller against spring tension between the guide bars when the roller is opposite the bars and the elevator cab is stopping at said floor, whereby the elevator entrance door will be opened with the gate of the elevator cab, said support including a base plate, a lever pivotally mounted on said base plate, a cylindrical member secured to said lever, said roller being axially mounted and movable on said References Cited in the file of this patent UNITED STATES PATENTS 1,232,903 Dunn July 10, 1917 1,876,438 Werner Sept. 6, 1932 1,911,792 Boedtcher May 30, 1933 2,307,353 Bond Jan. 5, 1943 2,899,021 OGrady Aug. 11, 1959 

